The N.B.A. is investigating whether Isiah Thomas, the president and coach of the Knicks, ordered a hard foul that touched off a brawl with the Denver Nuggets on Saturday night at Madison Square Garden, several people involved in the investigation said yesterday.

The Nuggets, according to those people, are pointing to an exchange between Thomas and the Nuggets’ Carmelo Anthony — part of which was captured by the MSG Network — that seemed to convey a threat. None of the people who spoke about the exchange were willing to be identified.

Ten players were ejected after the fight, which started when Mardy Collins, a Knicks rookie, clobbered J. R. Smith of the Nuggets as he was driving for a basket.

Some of these players, and possibly Thomas, are expected to receive suspensions today after a review of the videotape and interviews of players, coaches and security personnel.

The league is certain to punish Anthony, its leading scorer and one of its brightest young stars, for throwing a punch at Collins. As for Thomas, a Hall of Fame guard who is now fighting to hold on to his job, the situation is unusual because there is no known precedent for a team’s coach, let alone its president, to be punished for instigating a fight.

With 1 minute 32 seconds left, the MSG broadcast focused on Thomas while Denver’s Marcus Camby shot free throws. The Nuggets were leading, 117-100. Thomas, standing on the sideline, his arms folded and his jaw tight, bites his lip and starts talking to a Nuggets player. The player is not in the camera shot, but the broadcaster Mike Breen notes that Thomas is talking to Anthony.

There is no audio of Thomas, but in repeated viewing of the video he appears to say: “Hey, don’t go to the basket right now. It wouldn’t be a good idea.” Seconds later, Thomas cocks his head, holds out his right palm and, with a slight smile, adds, “Just letting you know.”

The broadcast did not capture the entire exchange, however, as the network toggled between cameras. Thomas also told Anthony that he “shouldn’t be in the game right now,” because the score was lopsided and the Knicks had removed most of their starters, according to an associate who spoke with Thomas yesterday. The message was intended as a plea not to embarrass the Knicks further. The associate was not authorized to speak on Thomas’s behalf and spoke on condition of anonymity.

Calvin Andrews, Anthony’s agent, confirmed that Anthony said Thomas had told him to stay away from the area under the basket. Andrews indicated that Anthony gave that account to N.B.A. officials. Thomas also spoke to league officials.

The issue for N.B.A. officials is how to interpret Thomas’s words, and his intent. Was Thomas merely advising a young star that he should not embarrass the Knicks by running up the score? Or was he issuing a warning?

After the game — but before Thomas’s comments came to light — Thomas gave reporters his account of that conversation with Anthony.

“I just said to him: ‘You’re up 19 with a minute and a half to go. You and Camby really shouldn’t be in the game right now.’ We had surrendered. And those guys shouldn’t have been in the game at that time,” Thomas said. “They were sticking it to us pretty good. They were having their way with us pretty good. I think J. R. Smith had just made one dunk where he reverses it and spins in the air. I thought that Mardy didn’t want to have our home crowd see that again and he fouled him.”

The Knicks were off yesterday, and team officials declined to comment on the incident or Thomas’s actions. Neither James L. Dolan, chairman of Madison Square Garden, which owns the Knicks, nor Steve Mills, the Garden president, will be commenting on the matter at any point, a company spokesman said.